Film from film rolls is often used in packaging applications. For example, the contents of a pallet can be bundled together with a stretch wrap film (e.g., a pre-stretched film or a post-stretched film) made from a polyethylene resin or other material. Conventionally, stretch wrap film is wrapped around a tubular core defining an axially extending roll axis passage of the film roll of substantially fixed dimensions. The film is subsequently unwound from the core in use in a packaging application. Dispensers can be installed in the core to aid in unwinding the film from the roll. Conventional dispensers have a hub that extends into a roll axis passage of the film roll and engages the core. A handle member is mounted on the hub for rotation with respect to the hub. The handle member can be held in the hand of a user who manually unwinds the film from the roll or attached to an automated wrapping apparatus such as a palletizer. As film is unwound from the roll, the hub and film roll rotate mutually and in a controlled fashion with respect to the handle member.
The use of cores in film rolls increases the overall cost of the film to the end user. Coreless film rolls are known to those skilled in the art and provide cost advantages over traditional film rolls. A coreless film roll has a roll axis passage, but no core inside the passage to keep its dimensions uniform. Because of the tendency of the film, and particularly pre-stretch film, to change dimensions after it is wound into the roll, the dimensions of roll axis passages in coreless film rolls are highly variable. Moreover, the roll axis passage may have significantly different dimensions at different locations along its length. Thus, traditional film dispensers that are only operable with roll axis passages adhering to strict dimensional requirements are not operable for use with coreless film rolls of varying internal dimensions. The roll axis passage may be too small to receive the dispenser hub or may cause damage to the film when the hub is inserted. If the roll axis passage is too much larger than the dispenser hub, the roll may rotate or “skip” relative to the hub in use, which is not desirable. Coreless film rolls also lack the structural rigidity of a rigid core. As a result, handling of coreless film rolls can cause bowing or other deformation of the roll, particularly as the roll is nearly used up. Moreover, it is essential that changeover from one film roll to the next be done quickly and accurately. A dispenser hub that cannot be rapidly and precisely applied will not be used by consumers of plastic film because of economic inefficiency.